One of the most common injuries sustained by humans and animals is the accidental penetration of the skin by foreign objects, such as pieces of metal, glass, wood, needles, pencil lead, bullets, BB pellets, nails, screws, fiberglass, paints and pigments. When part of the foreign body still protrudes outside the skin it can be removed fairly easily. However, when the foreign body has penetrated the skin with substantial projectile velocity so that it is completely embedded beneath the skin in deeper tissues, removal is often difficult. This is due to the fact that there may be variation in the direction and depth to which the foreign body has traveled. The presence of the entry wound is of help. When the entry wound is completely healed, locating the object becomes more difficult.
Utilizing currently available materials and techniques, a surgeon can encounter a great deal of difficulty in finding small embedded objects, often spending as much as one half to one and a half hours, or even longer, in the attempt to locate and remove the foreign body. This is true, even though pre-operative X-rays are taken in an effort to localize the position of the object.
Because of the difficulties described above, many surgeons, veterinarians, and podiatrists require fluoroscopic studies to be done in the operating room during the removal procedures. These often are long, drawn-out procedures, which undesirably subject the patients to prolonged anesthesia and excessive X-ray exposure.
Using the device and method of the invention, a preoperative X-ray study is made of the traumatized area, to precisely pinpoint the location of the foreign body and allow the surgeon thereafter to quickly effect its removal, often reducing to a few minutes procedures heretofore requiring extensive time, patience and effort.
The invention is a novel grid-like screen, formed of a material opaque to X-rays, preferably thin stainless steel but also tin-lead or lead-plated copper, and the method of use of the screen. When a patient presents a history to a doctor suggesting the possible presence of an embedded foreign body, an X-ray is taken to verify its presence or absence. If its presence is confirmed, then the invention comes into play. The screen is carefully placed over the anatomic part with a targeting element directed over the point of injury or entry wound or a marked point, these constituting a targeting mark. It is held in this position or taped in place. The anatomic part is then turned or manipulated so that the screen rests against the cassette holding the film. An X-ray image is taken, which will incorporate the grid pattern and fix the location of the foreign object with respect thereto in a two-dimensional plane. The screen is then re-positioned at right angles to its first orientation with the targeting element again aligned with the previously selected injury or marked point, and a second X-ray image is taken with the screen again positioned against the film cassette. These two X-ray images are used by the surgeon to triangulate the location of the foreign body, and determine and mark where the incision should be made in order to retrieve it. The surgeon can then quickly effect its removal. If, under certain circumstances, it is not possible to manipulate the anatomic part so that the screen rests directly against the film cassette, then the screen can rest between the X-ray source and the anatomic part. This is not the preferred method.
For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following detailed description of a preferred embodiment and to the accompanying drawings.